This invention relates generally to adjustable steering columns and more particularly to a locking device for an adjustable steering column assembly for a vehicle.
A problem with known adjustable steering columns is how to prevent them from moving when they are not supposed to and giving them free movement when they are supposed to, particularly in the case of steering columns that adjust up and down and fore and aft. Common systems in use rely either on simple friction clamping systems or on serrated or tooth locking mechanisms.
The common systems have a problem of giving sufficient friction to clamp, while still being able to move freely in the unlocked condition. Moreover, simple metal-to-metal systems tend to be poor in user feel and the addition of plastics such as plastics spacers tend to introduce creep and wear. Other known arrangements work on a serrated or toothed lock mechanism construction which are quite common on tilting steering columns. Such devices rely on the fixed and moving steering column parts having expensive splined teeth engaging with each other. There is a drawback that these are limited in adjustment position and are expensive.
The foregoing illustrates limitations known to exist in present adjustable steering column clamping systems. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.